Add Distribution API to Sentry Android Gradle Plugin (#986)

* Add Build Distribution API to Sentry Android Gradle Plugin

Add BuildDistributionExtension with enabledFor property to specify
which build variants should have build distribution enabled.

This commit only adds the API - no functionality is wired yet.

Usage:
```gradle
sentry {
  buildDistribution {
    enabledFor.set(["freeDebug", "paidRelease"])
  }
}
```

Closes EME-277

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

* Rename BuildDistribution to Distribution

- Rename BuildDistributionExtension to DistributionExtension
- Rename buildDistribution DSL to distribution
- Update tests and class names accordingly

* Apply spotless formatting

* Address PR review comments

- Rename enabledFor to enabledVariants for clarity
- Add documentation clarifying that global ignore settings
  have no relation to distribution settings
- Keep @experimental annotation for new APIs

* Import @experimental annotation and apply spotless formatting

- Import @experimental annotation in SentryPluginExtension for cleaner usage
- Apply spotless formatting to comment wrapping
- Use consistent short @experimental annotation form

---------

Co-authored-by: Claude <noreply@anthropic.com>

Author: runningcode

plugin-build/src/main/kotlin/io/sentry/android/gradle/extensions/DistributionExtension.kt

@@ -0,0 +1,19 @@
+package io.sentry.android.gradle.extensions
+
+import javax.inject.Inject
+import org.gradle.api.model.ObjectFactory
+import org.gradle.api.provider.SetProperty
+import org.jetbrains.annotations.ApiStatus.Experimental
+
+@Experimental
+open class DistributionExtension @Inject constructor(objects: ObjectFactory) {
+
+  /**
+   * Set of Android build variants that should have distribution enabled.
+   *
+   * Note: The global ignore settings (ignoredVariants, ignoredBuildTypes, ignoredFlavors) have no
+   * relation to distribution and do not affect which variants are enabled here.
+   */
+  val enabledVariants: SetProperty<String> =
+    objects.setProperty(String::class.java).convention(emptySet())
+}

plugin-build/src/main/kotlin/io/sentry/android/gradle/extensions/SentryPluginExtension.kt

@@ -113,6 +113,13 @@ abstract class SentryPluginExtension @Inject constructor(project: Project) {
     sizeAnalysisAction.execute(sizeAnalysis)
   }
 
+  val distribution: DistributionExtension = objects.newInstance(DistributionExtension::class.java)
+
+  @Experimental
+  fun distribution(distributionAction: Action<DistributionExtension>) {
+    distributionAction.execute(distribution)
+  }
+
   val vcsInfo: VcsInfoExtension = objects.newInstance(VcsInfoExtension::class.java)
 
   /** Configure the VCS information for build uploads. */

plugin-build/src/test/kotlin/io/sentry/android/gradle/extensions/DistributionExtensionTest.kt

@@ -0,0 +1,27 @@
+package io.sentry.android.gradle.extensions
+
+import kotlin.test.assertEquals
+import kotlin.test.assertTrue
+import org.gradle.testfixtures.ProjectBuilder
+import org.junit.Test
+
+class DistributionExtensionTest {
+
+  @Test
+  fun `enabledVariants is empty by default`() {
+    val project = ProjectBuilder.builder().build()
+    val extension = project.objects.newInstance(DistributionExtension::class.java)
+
+    assertTrue(extension.enabledVariants.get().isEmpty())
+  }
+
+  @Test
+  fun `enabledVariants can be configured with variant names`() {
+    val project = ProjectBuilder.builder().build()
+    val extension = project.objects.newInstance(DistributionExtension::class.java)
+
+    extension.enabledVariants.set(setOf("freeDebug", "paidRelease"))
+
+    assertEquals(setOf("freeDebug", "paidRelease"), extension.enabledVariants.get())
+  }
+}